Glycolysis. Splitting glucose to jumpstart cellular respiration презентация

Terms to keep in mind:
Glycolysis
Pyruvate
Phosphorylation
Glucose (hexose)
Fructose phosphate
Fructose 1,6 bisphosphate
Triose phosphate
Oxidation
Reduction
NAD

Glycolysis
The first step in cellular respiration
The splitting of glucose (with 6 carbons or 6C) into 2 pyruvate molecules (with 3 carbons each or 3C)

Glycolysis
Occurs in the cytoplasm of cells
Uses ATP but releases ATP as well
Uses 2 ATP but releases 4 ATP, so a net of 2 ATP in one process.
cytoplasm

Steps in Glycolysis
1. phosphorylation
Splitting of glucose (6C) into 2 triose phosphate (3C) molecules with usage of ATP
2. triose phophate to pyruvate
Transforming triose phosphate (3C) to pyruvate (3C)
Reduction of NAD

Step 1. Phosphorylation
Adding of phosphate groups to glucose to raise its energy level (make it more reactive – easier to split apart)

Step 1. Phosphorylation
Structures & processes involved:
Phosphate group

Step 1. Phosphorylation
1.a. One phosphate of ATP added to glucose and it becomes fructose-6-phosphate
(with the help of enzymes)
Triose phosphate (3C)
Triose phosphate (3C)

Step 1. Phosphorylation
1.b. One phosphate of ATP added to fructose-6-phosphate and it becomes fructose-1,6-bisphosphate
(with the help of enzymes)
Triose phosphate (3C)
Triose phosphate (3C)

Step 1. Phosphorylation
1.c. fructose-1,6-bisphosphate is split in the middle to form 2 triose phosphates
(with the help of enzyme)
Triose phosphate (3C)
Triose phosphate (3C)

Step 2. Triose Phosphate
to Pyruvate
Triose phosphate (3C) goes through a series of transformations (intermediates) to become a pyruvate (3C) molecule
2 triose phosphates go through the same process
4 ATP produced (2 for each)
2 NAD reduced to NADH (1 for each)
2 pyruvate molecules produced in the end
*this is the complete process. No need to memorize

Step 2. Triose Phosphate
to Pyruvate
2.a. one hydrogen in triose phosphate is removed and bind to NAD to form NADH
(2 NADH produced)
Triose phosphate
intermediate
this one!
phosphorylation
Triose phosphate is oxidised (lost hydrogen) while NAD is reduced (gains hydrogen)

Step 2. Triose Phosphate
to Pyruvate
2.a. each triose phosphate is phosphorylated again – each will have 2 phosphates in its structure
Triose phosphate
intermediate
This phosphate is not from an ATP molecule
phosphorylation

Step 2. Triose Phosphate
to Pyruvate
2.b. one phosphate group is removed from each intermediate and bind to ADP to form ATP
(2 ATPs produced)
phosphorylation
ADP + Pi = ATP

Step 2. Triose Phosphate
to Pyruvate
2.c. the last phosphate group is removed from the intermediate and bind to ADP to form ATP. Intermediate becomes pyruvate
(2 ATP produced)
(2 pyruvates produced)
phosphorylation
ADP + Pi = ATP

Net Energy Gain in GLycolysis
Products of GLycolysis
Fate of the pyruvate:
Pyruvate still contains a lot of chemical potential energy. If oxygen is present in the cell, pyruvate will enter mitochondrion for the next stage of aerobic respiration.